A General Framework for Flow Control in Wireless Networks
Abstract
Flow control and rate control for multimedia streaming, is an important issue in information transmission. Although the problem of flow control has been successfully addressed in wired networks, it is still open in wireless networks. Current widely accepted solutions assume that congestion is the only cause of packet loss and are not applicable to wireless networks in which the bulk of packet loss is due to errors at the physical layer. We show that this often results in bandwidth underutilization. In this thesis, we formulate flow control in wireless networks as a convex optimization problem. We then propose a new class of solutions that properly adjust the number of connections of a user, to fully utilize wireless bandwidth and minimize end-to-end packet loss. Our solution differs from existing schemes in the following ways: 1) It is theoretically guaranteed to be optimal, stable and scalable. In a network with arbitrary topology, arbitrary number of users, and arbitrary initial source rates, our proposed schemes guarantee all users' source rates to globally exponentially converge to an equilibrium. This convergence guarantees no congestion collapse in the network. 2) our proposed schemes are end-to-end and require modifications to neither infrastructure nor transport protocol stack. We have designed practical schemes for data transmission over wireless networks. Both users' rates and the number of connections they open are properly controlled to pursue equilibrium in the network. It is sufficient to control users' rates and their number of connections independently in two separate timescales to guarantee convergence to the desired equilibrium. This two timescale approach allows modification of the control law in one timescale without affecting the one in the other timescale, or the system's convergence.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 22, 2006
- Accession Number
- ADA477665
Entities
People
- Minghua Chen
Organizations
- University of California, Berkeley